Precise low level measurement of gaseous impurities in solid materials is an extremely difficult and time consuming task. By low level measurement is meant determination down to about 0.1 parts per million (ppm) by weight of gaseous impurity in the solid materials. In a commercial production unit, it is important to be able to obtain a precise and relatively quick determination of the amount of gaseous substance in solid materials in order to improve the purity of the final product.
One particularly important gaseous impurity determination is the measurement of hydrogen impurity in polysilicon solids such as beads, chunks, film, etc. High purity polysilicon beads are an important raw material in the production of semiconductor materials and devices.
Previously, it had taken up to 6 to 8 hours to determine the amount of hydrogen impurity in a sample of solid silicon. Constant operator attention was usually required during the analysis of the sample. Even with constant operator attention, the possibility of an error in analyzing the sample was great. Hence, a need existed for a reliable, less labor intensive way or detecting and determining low levels of hydrogen impurity in silicon.